LARE Irrigation Design Flashcards

What is the primary purpose of a pressure vacuum breaker (PVB) in a landscape irrigation system?

Answer: To prevent backflow contamination of the potable water supply

A pressure vacuum breaker prevents contaminated irrigation water from siphoning back into the potable water supply through backflow protection.

Which irrigation head type is most appropriate for large, open turf areas?

Answer: Rotor heads

Rotor heads are designed for large open turf areas because they throw water 15–50 feet using rotating streams, efficiently covering wide spaces.

What does 'precipitation rate' refer to in landscape irrigation design?

Answer: The rate at which irrigation heads apply water to an area, measured in inches per hour

Precipitation rate is the rate at which irrigation heads apply water to a given area, expressed in inches per hour, and must be matched to the soil's infiltration rate.

What is the typical operating pressure range for standard pop-up spray heads?

Answer: 30–45 PSI

Pop-up spray heads are designed to operate at 30–45 PSI; pressures outside this range cause misting, fogging, or reduced arc coverage.

Which soil texture has the highest water infiltration rate?

Answer: Sand

Sand has the largest particle size and greatest pore space of all soil textures, resulting in the highest infiltration rate but the lowest water retention.

What is the primary purpose of a master valve in an irrigation system?

Answer: To serve as a main supply shutoff that closes whenever the controller is not actively running a zone

A master valve installed at the main supply line automatically closes when no zones are running, preventing water loss from leaking or damaged downstream zone valves.

Which irrigation scheduling approach uses real-time or historical weather data to calculate plant water demand?

Answer: Evapotranspiration (ET)-based scheduling

ET-based scheduling uses evapotranspiration data derived from weather conditions to precisely calculate how much water the landscape needs, avoiding over- or under-irrigation.